Check for updates on a timer, not only at startup

checkForUpdate() ran once in onMount, so an app left open for days would never
notice a release until it was restarted. A setInterval re-checks every 6 hours
while the app is running.

The periodic check skips itself while a download/install is in flight (so it
can't swap the update object out from under it), and clears a prior dismissal
when it finds a version newer than the one on screen — dismissing v0.10.2
shouldn't hide v0.10.3. It stays silent otherwise: the existing banner is the
only surfacing, and it appears only when check() returns an update.

Folded into the v0.10.2 release alongside the updater-notes work.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: sparkly-quasar

CHANGELOG.md

@@ -17,6 +17,10 @@ The heading must be exactly `## vX.Y.Z`, matching the tag. Newest on top.
   version number; from here on it shows the actual list of what's new — the notes
   you're reading. (You're seeing this because you updated *to* the version that
   added it, so this is the first time it appears.)
+- **The app now checks for updates on its own while it's open**, every few hours,
+  so a machine left running for days still finds out about a new version without
+  being restarted. The check is silent — you'll only ever notice it when there's
+  actually something new.
 
 ## v0.10.1
 

ROADMAP.md

@@ -136,6 +136,12 @@ non-negotiables, each with a test:
   GitHub page after publishing (see `RELEASING.md`) so they don't clutter the
   in-app notes. Seeds the renderer: rich notes appear on the *next* update after
   this one, since the prompt belongs to the installed version.
+- **Update checks now run on a timer, not just at startup.** `checkForUpdate` was
+  called once in `onMount`, so an app left open for days never noticed a release.
+  A `setInterval` (6 h) re-checks while running; it skips a check that's mid-install
+  and clears a prior dismissal when a genuinely newer version turns up, so
+  dismissing one version doesn't hide the next. Silent — it only surfaces when
+  `check()` returns something.
 
 ## Shipped in v0.10.1
 

src/routes/+page.svelte

@@ -274,6 +274,11 @@
   let updateBusy = $state(false);
   let updateMsg = $state("");
   let updateDismissed = $state(false);
+  // Re-check on a timer so a machine that stays open for days still learns about
+  // a release without being restarted. Six hours is often enough to catch a
+  // release the same day without hammering GitHub.
+  let updateTimer: ReturnType<typeof setInterval> | null = null;
+  const UPDATE_CHECK_INTERVAL_MS = 6 * 60 * 60 * 1000;
 
   // companion
   let cMessages = $state<ChatMsg[]>([]);
@@ -356,6 +361,7 @@
   onMount(() => {
     interactionClasses().then((c) => (classesVocab = c));
     checkForUpdate();
+    updateTimer = setInterval(checkForUpdate, UPDATE_CHECK_INTERVAL_MS);
     dontShowDisclaimer = localStorage.getItem(HIDE_DISCLAIMER_KEY) === "1";
     companionOff = localStorage.getItem(COMPANION_OFF_KEY) === "1";
     companionChoiceMade = localStorage.getItem(COMPANION_CHOICE_KEY) === "1";
@@ -373,6 +379,7 @@
       un.then((f) => f());
       unPaired.then((f) => f());
       if (lsTimer) clearInterval(lsTimer);
+      if (updateTimer) clearInterval(updateTimer);
     };
   });
 
@@ -391,8 +398,16 @@
   }
 
   async function checkForUpdate() {
+    // Leave a download/install alone — re-checking mid-flight would swap the
+    // object out from under it.
+    if (updateBusy) return;
     try {
-      update = await check();
+      const found = await check();
+      // If a timer tick turns up a version newer than the one already on screen,
+      // surface it even if the user dismissed the previous banner — dismissing
+      // v0.10.2 shouldn't hide v0.10.3.
+      if (found && found.version !== update?.version) updateDismissed = false;
+      update = found;
     } catch (_) {
       // offline, or no published release with an updater manifest yet — ignore
     }